It is well known in the prior art to provide a pleural drainage apparatus which incorporates three chambers, namely, a collection chamber, an underwater seal chamber and a manometer chamber. Early patents disclosing such devices are U.S. Pat. Nos. 3,363,626 and 3,363,627. The apparatus shown in such patents incorporates an integrally formed device and incorporates a large collection chamber for collecting fluids drained from the pleural cavity through a thoracotomy tube, a second chamber connected to the collection chamber which protects the pleural cavity from being subject to atmospheric pressure and known as an underwater seal chamber and a third chamber connected to the underwater seal chamber and known as a pressure manometer chamber which serves to regulate the degree of negative pressure within the pleural cavity. This type of apparatus has been highly successful in both removing fluids from the pleural cavity and in maintaining the desired degree of negativity within the pleural cavity.
It will be noted that in such well known prior art devices both the pressure manometer chamber and underwater seal chamber must be prefilled with liquid such as water prior to use of the device. It is essential that the correct amount of water be put in these chambers as any excess in the amount of water or failure to fill the chambers to the correct level can result in improper operation of the device and inability to maintain the proper degree of negativity within the pleural cavity. Thus, there has been a clear need in the prior art for a mechanism which will permit a safe, fast filling procedure to bring the liquid level in the manometer chamber and underwater seal chamber to the correct level and prevent overfilling or spilling of the liquid from one chamber to another.